吐纳麝香对东海原甲藻的毒性作用机制

Toxic mechanism of tonalide on Prorocentrum donghaiense

为研究吐纳麝香(AHTN)对海洋微藻的毒性作用机制,以东海原甲藻(Prorocentrum donghaiense)为受试对象,测定5种浓度的AHTN(1,10,50,200和400μg/L)对微藻的生长、光合色素含量、细胞形态结构、细胞膜通透性、抗氧化系统和光合系统的影响.结果表明,AHTN显著抑制东海原甲藻的生长,对东海原甲藻具有高毒性(96h-EC50=48.21μg/L),其毒性作用机制为抑制光合色素产生,破坏其细胞结构和细胞膜完整性,诱发抗氧化系统响应,影响光合作用性能.其中,1μg/L AHTN处理对东海原甲藻生长有促进作用,1和10μg/L AHTN处理促进光合色素合成,并使超氧化物歧化酶活性和部分光合参数升高.低浓度AHTN(1μg/L)可能会诱导东海原甲藻赤潮爆发,高浓度AHTN(10~400μg/L)则会抑制该藻种群生长,从而对海洋生态系统产生潜在威胁.

Prorocentrum donghaiense was selected to study the toxic mechanism of tonalide(AHTN) on marine microalgae. Five concentrations(1, 10, 50, 200 and 400μg/L) of AHTN were tested to evaluate its influence on the growth, photosynthetic pigment content, cell morphology and structure, cell membrane permeability and the antioxidant and photosynthetic systems. The results showed that AHTN significantly inhibited the growth of P. donghaiense with high toxicity(96 h-EC50 = 48.21μg/L). The mechanism of realization of the algal toxicity of AHTN is the inhibition of photosynthetic pigment production, the destruction of cell structure and cell membrane integrity, the induction of antioxidant system response, and the effect of photosynthe performance. However,treatment with 1μg/L AHTN treatment promoted the growth of P. donghaiense. Meanwhile, treatment with 1μg/L and 10μg/L AHTN promoted the synthesis of photosynthetic pigments and increased the activity of superoxide dismutase as well as some photosynthetic parameters. In conclusion, low concentrations of AHTN(1μg/L) may induce red tides of P. donghaiense, while high concentrations of AHTN(10~400μg/L) could inhibit the population growth of this algae and cause a potential threat to marine ecosystems.